Endpoints in a modern communication network, such as telephones and computers supporting telephony, are typically addressed by a unique string of characters. For example, a telephone endpoint may be addressed by a unique telephone number. Such telephone numbers are typically entered into databases, such as contact lists, for easy access. However, these numbers are typically entered in a non-standardized format, which may preclude an efficient database query for the purpose of calling line identification resolution when a call is received at the endpoint.